de.lmu.ifi.dbs.elki.database
Class QueryUtil

java.lang.Object
  de.lmu.ifi.dbs.elki.database.QueryUtil

public final class QueryUtil
extends Object

Static class with utilities related to querying a database.

Constructor Summary

QueryUtil()

Method Summary

static <O,D extends Distance<D>> DistanceQuery<O,D>	getDistanceQuery(Database database, DistanceFunction<? super O,D> distanceFunction, Object... hints) Get a distance query for a given distance function, automatically choosing a relation.
static <O,D extends Distance<D>> KNNQuery<O,D>	getKNNQuery(Database database, DistanceFunction<? super O,D> distanceFunction, Object... hints) Get a KNN query object for the given distance function.
static <O,D extends Distance<D>> KNNQuery<O,D>	getKNNQuery(Relation<O> relation, DistanceFunction<? super O,D> distanceFunction, Object... hints) Get a KNN query object for the given distance function.
static <O,D extends Distance<D>> KNNQuery<O,D>	getLinearScanKNNQuery(DistanceQuery<O,D> distanceQuery) Get a linear scan query for the given distance query.
static <O,D extends Distance<D>> RangeQuery<O,D>	getLinearScanRangeQuery(DistanceQuery<O,D> distanceQuery) Get a linear scan query for the given distance query.
static <O,D extends Distance<D>> RangeQuery<O,D>	getRangeQuery(Database database, DistanceFunction<? super O,D> distanceFunction, Object... hints) Get a range query object for the given distance function.
static <O,D extends Distance<D>> RangeQuery<O,D>	getRangeQuery(Relation<O> relation, DistanceFunction<? super O,D> distanceFunction, Object... hints) Get a range query object for the given distance function.
static <O,D extends Distance<D>> RKNNQuery<O,D>	getRKNNQuery(Relation<O> relation, DistanceFunction<? super O,D> distanceFunction, Object... hints) Get a rKNN query object for the given distance function.
static <O,D extends Distance<D>> SimilarityQuery<O,D>	getSimilarityQuery(Database database, SimilarityFunction<? super O,D> similarityFunction, Object... hints) Get a similarity query, automatically choosing a relation.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

QueryUtil

public QueryUtil()

Method Detail

getDistanceQuery

public static <O,D extends Distance<D>> DistanceQuery<O,D> getDistanceQuery(Database database,
                                                                            DistanceFunction<? super O,D> distanceFunction,
                                                                            Object... hints)

Get a distance query for a given distance function, automatically choosing a relation.

Type Parameters:

O - Object type

D - Distance type

Parameters:

database - Database

distanceFunction - Distance function

hints - Optimizer hints

Returns:

Distance query

getSimilarityQuery

public static <O,D extends Distance<D>> SimilarityQuery<O,D> getSimilarityQuery(Database database,
                                                                                SimilarityFunction<? super O,D> similarityFunction,
                                                                                Object... hints)

Get a similarity query, automatically choosing a relation.

Type Parameters:

O - Object type

D - Distance type

Parameters:

database - Database

similarityFunction - Similarity function

hints - Optimizer hints

Returns:

Similarity Query

getKNNQuery

public static <O,D extends Distance<D>> KNNQuery<O,D> getKNNQuery(Database database,
                                                                  DistanceFunction<? super O,D> distanceFunction,
                                                                  Object... hints)

Get a KNN query object for the given distance function. When possible, this will use an index, but it may default to an expensive linear scan. Hints include:

• Integer: maximum value for k needed
• DatabaseQuery.HINT_BULK bulk query needed

Type Parameters:

O - Object type

D - Distance type

Parameters:

database - Database

distanceFunction - Distance function

hints - Optimizer hints

Returns:

KNN Query object

getKNNQuery

public static <O,D extends Distance<D>> KNNQuery<O,D> getKNNQuery(Relation<O> relation,
                                                                  DistanceFunction<? super O,D> distanceFunction,
                                                                  Object... hints)

Get a KNN query object for the given distance function. When possible, this will use an index, but it may default to an expensive linear scan. Hints include:

• Integer: maximum value for k needed
• DatabaseQuery.HINT_BULK bulk query needed

Type Parameters:

O - Object type

D - Distance type

Parameters:

relation - Relation used

distanceFunction - Distance function

hints - Optimizer hints

Returns:

KNN Query object

getRangeQuery

public static <O,D extends Distance<D>> RangeQuery<O,D> getRangeQuery(Database database,
                                                                      DistanceFunction<? super O,D> distanceFunction,
                                                                      Object... hints)

Get a range query object for the given distance function. When possible, this will use an index, but it may default to an expensive linear scan. Hints include:

• Range: maximum range requested
• DatabaseQuery.HINT_BULK bulk query needed

Type Parameters:

O - Object type

D - Distance type

Parameters:

database - Database

distanceFunction - Distance function

hints - Optimizer hints

Returns:

KNN Query object

getRangeQuery

public static <O,D extends Distance<D>> RangeQuery<O,D> getRangeQuery(Relation<O> relation,
                                                                      DistanceFunction<? super O,D> distanceFunction,
                                                                      Object... hints)

Get a range query object for the given distance function. When possible, this will use an index, but it may default to an expensive linear scan. Hints include:

• Range: maximum range requested
• DatabaseQuery.HINT_BULK bulk query needed

Type Parameters:

O - Object type

D - Distance type

Parameters:

relation - Relation used

distanceFunction - Distance function

hints - Optimizer hints

Returns:

KNN Query object

getRKNNQuery

public static <O,D extends Distance<D>> RKNNQuery<O,D> getRKNNQuery(Relation<O> relation,
                                                                    DistanceFunction<? super O,D> distanceFunction,
                                                                    Object... hints)

Get a rKNN query object for the given distance function. When possible, this will use an index, but it may default to an expensive linear scan. Hints include:

• Integer: maximum value for k needed
• DatabaseQuery.HINT_BULK bulk query needed

Type Parameters:

O - Object type

D - Distance type

Parameters:

relation - Relation used

distanceFunction - Distance function

hints - Optimizer hints

Returns:

RKNN Query object

getLinearScanKNNQuery

public static <O,D extends Distance<D>> KNNQuery<O,D> getLinearScanKNNQuery(DistanceQuery<O,D> distanceQuery)

Get a linear scan query for the given distance query.

Type Parameters:

O - Object type

D - Distance type

Parameters:

distanceQuery - distance query

Returns:

KNN query

getLinearScanRangeQuery

public static <O,D extends Distance<D>> RangeQuery<O,D> getLinearScanRangeQuery(DistanceQuery<O,D> distanceQuery)

Get a linear scan query for the given distance query.

Type Parameters:

O - Object type

D - Distance type

Parameters:

distanceQuery - distance query

Returns:

Range query